JPH08168668A - Vapor heater - Google Patents

Abstract

PURPOSE: To provide a vapor heater for controlling the heating temperature with a high accuracy without delay in time for changing the vapor heating temperature. CONSTITUTION: A pressure driving section 9 of a pressure regulating valve 2 is connected with the vicinity of an ejector 7 by a pressure communicating pipe 8. A secondary pressure connecting valve 11 as an atmosphere sucking means is installed on the pressure communicating pipe 8 through a pipe 10 communicating with atmosphere. The secondary pressure regulating valve 11 is opened when the pressure on the secondary side is lowered to be lower than the set value to suck the atmosphere from the piping 10 and lower the degree of vacuum of a pressure chamber 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to heating an object to be heated in a heat exchanger with steam, and particularly, the heating temperature thereof is 100.
The present invention relates to a steam heating device suitable for a relatively low temperature of about C. Specifically, it is used for steam heating of various reaction kettles used for polymerization reaction, food distilling devices, concentrating devices, and sterilizing devices. In these cases, the object to be heated often suffers from thermal damage or composition change due to a slight temperature change, and it was necessary to maintain the heating temperature with high accuracy.

[0002]

2. Description of the Related Art As a conventional steam heating device, for example, one disclosed in Japanese Patent Laid-Open No. 3-241202 has been used. This is one in which a pressure reducing valve, a heating container, and an ejector-type vacuum pump are sequentially connected, and the pressure drive part of the pressure reducing valve and the vicinity of the ejector are connected by a pressure communication pipe, and the temperature of water passing through the ejector is controlled. Simply changing the suction force of the ejector changes the pressure drive unit of the pressure reducing valve via the pressure communication pipe, and the set pressure of the pressure reducing valve can be changed automatically, making it easy to change the heating steam temperature. Is what you can do.

[0003]

The above-described conventional steam heating device has a problem that it takes time to change the heating temperature, which causes a time delay in temperature control. This is because when the heating temperature is changed, the temperature of the fluid passing through the ejector must be changed. Actually, by supplying cooling water to the tank communicating with the ejector, the fluid in the tank is changed. There is a time delay because the temperature of the fluid passing through the ejector is changed after the temperature is changed.

Therefore, a technical object of the present invention is to obtain a steam heating apparatus in which the steam heating temperature is changed promptly and there is no time delay.

[0005]

The structure of the steam heating apparatus of the present invention is as follows. A pressure control valve, a heat exchanger, and an ejector-type vacuum pump are sequentially connected, and the pressure drive part of the pressure control valve and the vicinity of the ejector are connected by a pressure communication pipe. Atmosphere suction means for sucking air is attached.

[0006]

With the atmospheric suction means attached to the pressure communication pipe, when the amount of atmospheric air sucked from the atmospheric suction means is small, the pressure drive portion of the pressure regulating valve is almost displaced while the vacuum degree of the pressure communication pipe remains high. However, the set pressure of the pressure control valve also maintains a high degree of vacuum, but when the suction amount from the atmospheric suction means increases, the degree of vacuum in the pressure communication pipe decreases, the pressure drive section is displaced, and the set pressure of the pressure control valve is The degree of vacuum is low. Therefore, by increasing or decreasing the amount of atmospheric suction from the atmospheric suction means, the pressure of the pressure control valve can be set to a low vacuum level or a high vacuum level, and the temperature of the fluid passing through the ejector can be changed. The steam pressure, that is, the steam temperature can be quickly changed by simply adjusting the atmospheric suction means without changing the temperature.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrated embodiment will be described in detail. Heat exchanger 1
A steam supply pipe 5 is connected via a pressure regulating valve 2, a pressure reducing valve 3 and an opening / closing valve 4. The lower part of the heat exchanger 1 is connected to the ejector vacuum pump 6. The pressure communication pipe 8 is connected to the pressure drive unit 9 of the pressure regulating valve 2 from the vicinity of the ejector 7. A secondary pressure control valve 11 as an air suction means is attached to the pressure communication pipe 8 via a pipe line 10 communicating with the atmosphere.

The pressure regulating valve 2 urges the diaphragm 12 in the form of a thin metal plate to the right by a tension coil spring 13 to form a pressure chamber 14 in the right chamber of the diaphragm 12 and connect the pressure communication pipe 8. The secondary side pressure of the pressure control valve 2, that is, the pressure on the heat exchanger 1 side acts on the left side surface of the diaphragm 12, and when the secondary side pressure becomes lower than a set value, the diaphragm 12 is displaced to the left side. By opening the pressure control valve 2, steam is supplied from the steam supply pipe 5 to the heat exchanger 1 to restore the steam pressure in the heat exchanger 1 to a set value, and the pressure in the heat exchanger 1 is set. When the value is restored to the value, the diaphragm 12 is displaced to the right and the pressure regulating valve 2 is closed.

The secondary pressure adjusting valve 11 attached to the pressure communication pipe 8 opens when the secondary pressure, that is, the pressure in the pressure communication pipe 8 falls below a set value, and sucks atmospheric air from the pipe line 10 to apply pressure. In the communication pipe 8, and by extension, in the pressure chamber 14 of the pressure regulating valve 2.
The degree of vacuum is lowered by increasing the pressure of No. 1, and the set pressure can be arbitrarily adjusted by appropriately operating a pressure setting unit (not shown).

The ejector-type vacuum pump 6 is composed of an ejector 7 having a built-in nozzle, a tank 15, a circulation pump 16 and a circulation passage 17 connecting these. The lower part of the tank 15 and the suction port side of the circulation pump 16 are connected, and the discharge side of the circulation pump 16 is connected to the ejector 7. The ejector-type vacuum pump 6 is configured to generate a suction force in the ejector 7 by circulating the fluid in the tank 15 with the circulation pump 16 and passing it through the nozzle portion in the ejector 7. A surplus liquid discharge passage 21 is connected via a valve 20 to the circulation passage 17 connected to the discharge port of the circulation pump 16. Tank 1
A temperature sensor 22 for detecting the internal liquid temperature is attached to 5, and a cooling water supply pipe 23 is connected to the upper portion thereof via an automatic valve 25.

Next, the operation will be described. The pressure adjusting valve 2 heats the steam for reducing pressure from the steam supply pipe 5 to a low pressure by the pressure reducing valve 3.
By supplying the heat to the heat exchanger 1 via the heat exchanger 1 and driving the ejector-type vacuum pump 6 to generate suction force by the ejector 7 to maintain the inside of the steam pipe in the heat exchanger 1 at a predetermined degree of vacuum, The object to be heated in the heat exchanger 1 is heated with low temperature steam. The steam that has heated the object to be heated is condensed into condensed water, and is sucked by the ejector 7 of the ejector-type vacuum pump 6 and reaches the tank 15.

By increasing the degree of vacuum generated by the ejector-type vacuum pump 6 by a predetermined value from the degree of vacuum required for low temperature heating in the heat exchanger 1, the secondary pressure adjusting valve 11
It is possible to constantly suck a certain amount of air to maintain the required degree of vacuum in the heat exchanger 1. Then, the suction amount of the atmosphere from the secondary pressure adjusting valve 11 is made smaller than the above-mentioned fixed amount, thereby increasing the vacuum degree of the pressure communicating pipe 8 and by extension the pressure chamber 14 of the pressure adjusting valve 2 to set the pressure adjusting valve 2. The degree of vacuum can also be increased. In addition, the secondary pressure control valve 11
When the amount of suction of the atmosphere from is increased, the vacuum degree of the pressure chamber 14 is lowered and the set vacuum degree of the pressure adjusting valve 2 can be lowered. By changing the setting of the secondary pressure adjusting valve 11 in this way, the set vacuum degree of the pressure adjusting valve 2 can be changed, and the time delay can be achieved without changing the temperature of the fluid passing through the ejector 7. Heat exchanger 1 without occurring
It is possible to control the heating steam pressure or steam temperature supplied to.

[0013]

According to the present invention, the set pressure of the pressure adjusting valve can be adjusted only by adjusting the amount of atmospheric suction from the atmospheric suction means, and it is necessary to change the temperature of the fluid passing through the ejector. Therefore, the time required for changing the fluid temperature becomes unnecessary, and there is no time delay in steam temperature control.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a steam heating device of the present invention.

[Explanation of symbols]

 1 Heat Exchanger 2 Pressure Control Valve 5 Steam Supply Pipe 6 Ejector Type Vacuum Pump 7 Ejector 8 Pressure Communication Pipe 9 Pressure Drive Unit 11 Secondary Pressure Control Valve 12 Diaphragm 13 Extension Coil Spring 14 Pressure Chamber 15 Tank 16 Circulation Pump

Claims (1)

[Claims] 1. A pressure communication pipe in which a pressure control valve, a heat exchanger, and an ejector-type vacuum pump are sequentially connected, and a pressure drive portion of the pressure control valve and the vicinity of the ejector are connected by a pressure communication pipe. A vapor heating device, characterized in that an atmospheric suction means for sucking a desired amount of atmospheric air is attached to the steam heating device.